chronic Involving a stimulus that is lingering or continues for a long time; oftensignifies periods from several weeks to years, depending on the reproductivelife cycle of the aquatic species. Can be used to define either the exposure orthe response to an exposure (effect). The chronic aquatic toxicity test is used tostudy the effects of continuous, long-term exposure of a chemical or otherpotentially toxic material on aquatic organisms (Rand and Petrocelli 1985). [source: NOAA]

chronicchronic